A rare and expensive jewelry item known as a reverse intaglio crystal usually comprises a hand-carved and hand-painted glass or crystal set in a precious metal bezel or ring. An "intaglio" has a recessed figure cut in stone or some other hard substance so that the figure is hollowed out in three dimensions. In a reverse intaglio, the figure is cut into the reverse side of the stone.
In the finished reverse intaglio item produced by the method of the present invention, a three-dimensional image of something of interest, such as an animal, a house, or a tree, is visible through the face of the stone, creating the accurate visual impression that the image is actually within, not under, the stone. In a reverse intaglio made by traditional methods, the hand-carving and hand-painting is done in reverse (that is, on the underside of the stone) using a technique known as "eglomise." An image is carved in three dimensions into the underside of a small glass, crystal or precious stone cabochon. The image is then painted in reverse inside the cabochon. The paint is applied to the carved surface of the recess within the cabochon. The image is seen through the face (top) of the crystal.
It is as if a scene was painted on the inside of a window for viewing from the outside, which is precisely what the French word "eglomise" historically defined. In a reverse intaglio, the fact that the image is carved into the underside of the stone in three dimensions before painting is what conveys the correct visual impression that the scene actually resides within the stone.
Reverse intaglios have been relatively rare and expensive because they have been made entirely by hand. They are often quite small, about the size of a U.S. dime, requiring extreme precision in the acts of cutting and painting in order to produce a visually pleasing product. Painting an image in reverse, particularly on a small, three dimensional surface, is a developed and relatively rare skill. In order for reverse intaglios to become more widely available and affordable, a way had to be found to make the intaglios more efficiently without sacrificing the intricate three-dimensional carving and painting detail and the traditional high-quality character of the image within the stone.